See-through metrology systems, apparatus, and methods for optical devices

ABSTRACT

Embodiments of the present disclosure relate to optical devices for augmented, virtual, and/or mixed reality applications. In one or more embodiments, an optical device metrology system is configured to measure a plurality of see-through metrics for optical devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent applicationSer. No. 63/092,421, filed Oct. 15, 2020, which is herein incorporatedby reference in its entirety.

BACKGROUND Field

Embodiments of the present disclosure relate to optical devices foraugmented, virtual, and/or mixed reality applications. In one or moreembodiments, an optical device metrology system is configured to measurea plurality of see-through metrics for optical devices.

Description of the Related Art

Virtual reality is generally considered to be a computer generatedsimulated environment in which a user has an apparent physical presence.A virtual reality experience can be generated in 3D and viewed with ahead-mounted display (HMD), such as glasses or other wearable displaydevices that have near-eye display panels as lenses to display a virtualreality environment that replaces an actual environment.

Augmented reality, however, enables an experience in which a user canstill see through the display lenses of the glasses or other HMD deviceto view the surrounding environment, yet also see images of virtualobjects that are generated for display and appear as part of theenvironment. Augmented reality can include any type of input, such asaudio and haptic inputs, as well as virtual images, graphics, and videothat enhances or augments the environment that the user experiences. Asan emerging technology, there are many challenges and design constraintswith augmented reality.

One such challenge is displaying a virtual image overlaid on an ambientenvironment. Augmented waveguide combiners are used to assist inoverlaying images. Generated light is in-coupled into an augmentedwaveguide combiner, propagated through the augmented waveguide combiner,out-coupled from the augmented waveguide combiner, and overlaid on theambient environment. Light is coupled into and out of augmentedwaveguide combiners using surface relief gratings. The intensity of theout-coupled light may not be adequately controlled.

Accordingly, there is a need in the art for optical device metrologysystems and methods.

SUMMARY

Embodiments of the present disclosure relate to optical devices foraugmented, virtual, and/or mixed reality applications. In one or moreembodiments, an optical device metrology system is configured to measurea plurality of see-through metrics for optical devices.

In one implementation, an optical device metrology system includes astage configured to move a tray along a stage path, a first light enginemounted above the stage path and configured to direct upper light beamstoward the stage path, and a second light engine mounted below the stagepath and configured to direct lower light beams toward the stage path.The optical device metrology system includes a detector mounted abovethe stage path and configured to receive projected light beams projectedfrom the stage path, and a controller in communication with the stage,the first light engine, the second light engine, and the detector. Thecontroller includes instructions that, when executed, cause the stage toposition an optical device above the second light engine to align theoptical device with the second light engine, and the second light engineto direct first light beams from the second light engine and toward theoptical device. The instructions also cause the detector to capture aplurality of first images of the first light beams that project from theoptical device as first projected light beams, and the stage to positionthe optical device away from the second light engine to misalign theoptical device from the second light engine. The instructions also causethe second light engine to direct second light beams from the secondlight engine and toward the detector, the detector to capture aplurality of second images of the second light beams, and comparing ofthe plurality of second images with the plurality of first images todetermine a see-through transmittance metric of the optical device.

In one implementation, an optical device metrology system includes astage configured to move a tray along a stage path, and a first lightengine mounted above the stage path and configured to direct upper lightbeams toward the stage path. The optical device metrology systemincludes a second light engine mounted below the stage path andconfigured to direct lower light beams toward the stage path, and adetector mounted above the stage path and configured to receiveprojected light beams projected from the stage path. The detector isaligned with the second light engine and misaligned from the first lightengine.

In one implementation, a method of analyzing optical devices includespositioning an optical device above a light engine to align the opticaldevice with the light engine, and directing first light beams from thelight engine and toward the optical device. The method includescapturing a plurality of first images of the first light beams thatproject from the optical device as first projected light beams using adetector, and positioning the optical device away from the light engineto misalign the optical device from the light engine. The methodincludes directing second light beams from the light engine and towardthe detector, capturing a plurality of second images of the second lightbeams, and comparing the plurality of second images with the pluralityof first images to determine a see-through transmittance metric of theoptical device.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope, and may admit to other equally effective embodiments.

FIG. 1A is a perspective, frontal view of a substrate, according to oneimplementation.

FIG. 1B is a perspective, frontal view of an optical device, accordingto one implementation.

FIG. 2 is a schematic view of an optical device metrology system,according to one implementation.

FIG. 3A is a schematic partial cross-sectional view of the firstsubsystem shown in FIG. 2, according to one implementation.

FIG. 3B is a schematic partial cross-sectional view of the secondsubsystem shown in FIG. 2, according to one implementation.

FIG. 3C is a schematic partial cross-sectional view of the thirdsubsystem shown in FIG. 2, according to one implementation.

FIG. 4A is a schematic view of a configuration of the first subsystemshown in FIGS. 2 and 3A, according to one implementation.

FIG. 4B is a schematic view of a configuration of the first subsystemshown in FIGS. 2 and 3A, according to one implementation.

FIG. 4C is a schematic view of a configuration of the first subsystemshown in FIGS. 2 and 3A, according to one implementation.

FIG. 4D is a schematic view of a configuration of the first subsystemshown in FIGS. 2 and 3A, according to one implementation.

FIG. 4E is a schematic view of a configuration of the second subsystemshown in FIGS. 2 and 3B, according to one implementation.

FIG. 4F is a schematic view of a configuration of the third subsystemshown in FIGS. 2 and 3C, according to one implementation.

FIG. 4G is a schematic view of a configuration of the third subsystemshown in FIGS. 2 and 3C, according to one implementation.

FIG. 5 is a schematic view of an image, according to one implementation.

FIGS. 6A-6C are schematic views of images, according to oneimplementation.

FIGS. 7A-7C are schematic views of images, according to oneimplementation.

FIG. 8 is a schematic view of an image, according to one implementation.

FIGS. 9A-9C are schematic views of images, according to oneimplementation.

FIG. 10 is a schematic block diagram view of a method of analyzingoptical devices, according to one implementation.

FIG. 11 is a schematic block diagram view of a method of analyzingoptical devices, according to one implementation.

FIG. 12 is a schematic block diagram view of a method of analyzingoptical devices, according to one implementation.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure relate to optical devices foraugmented, virtual, and/or mixed reality applications. In one or moreembodiments, an optical device metrology system is configured to measurea plurality of see-through metrics for optical devices.

FIG. 1A is a perspective, frontal view of a substrate 101, according toone implementation. The substrate includes a plurality of opticaldevices 100 disposed on a surface 103 of the substrate 101. The opticaldevices 100 are waveguide combiners utilized for virtual, augmented,and/or mixed reality. The optical devices 100 may be part of thesubstrate 101 such that the optical devices 100 can be cut to beseparated from the substrate 101.

FIG. 1B is a perspective, frontal view of an optical device 100,according to one implementation. It is to be understood that the opticaldevices 100 described herein are exemplary optical devices and thatother optical devices (such as optical devices other than waveguidecombiners) may be used with or modified to accomplish aspects of thepresent disclosure.

The optical device 100 includes a plurality of optical device structures102 disposed on a surface 103 of a substrate 101. The optical devicestructures 102 may be nanostructures having sub-micron dimensions (e.g.,nano-sized dimensions). Regions of the optical device structures 102correspond to one or more gratings 104, such as a first grating 104 a, asecond grating 104 b, and a third grating 104 c. In one embodiment,which can be combined with other embodiments, the optical device 100includes at least the first grating 104 a corresponding to an inputcoupling grating and the third grating 104 c corresponding to an outputcoupling grating. In one embodiment, which can be combined with otherembodiments described herein, the optical device 100 also includes thesecond grating 104 b corresponding to an intermediate grating. Theoptical device structures 102 may be angled or binary. The opticaldevice structures 102 are rectangular. The optical device structures 102may have other shapes including, but not limited to, circular,triangular, elliptical, regular polygonal, irregular polygonal, and/orirregular shaped cross-sections.

In operation (such as for augmented reality glasses), the input couplinggrating 104 a receives incident beams of light (a virtual image) havingan intensity from a microdisplay. The incident beams are split by theoptical device structures 102 into T1 beams that have all of theintensity of the incident beams in order to direct the virtual image tothe intermediate grating 104 b (if utilized) or the output couplinggrating 104 c. In one embodiment, which can be combined with otherembodiments, the T1 beams undergo total-internal-reflection (TIR)through the optical device 100 until the T1 beams come in contact withthe optical device structures 102 of the intermediate grating 104 b. Theoptical device structures 102 of the intermediate grating 104 b diffractthe T1 beams to T−1 beams that undergo TIR through the optical device100 to the optical device structures 102 of the output coupling grating104 c. The optical device structures 102 of the output coupling grating104 c outcouple the T−1 beams to the user's eye to modulate the field ofview of the virtual image produced from the microdisplay from the user'sperspective and further increase the viewing angle from which the usercan view the virtual image. In one embodiment, which can be combinedwith other embodiments, the T1 beams undergo total-internal-reflection(TIR) through the optical device 100 until the T1 beams come in contactwith the optical device structures 102 of the output coupling gratingand are outcoupled to modulate the field of view of the virtual imageproduced from the microdisplay.

To facilitate ensuring that the optical devices 100 meet image qualitystandards, metrology metrics of the fabricated optical devices 100 areobtained prior to use of the optical devices 100.

FIG. 2 is a schematic view of an optical device metrology system 200,according to one implementation. Embodiments of the optical devicemetrology system 200 described herein provide for the ability to obtainmultiple metrology metrics with increased throughput. The metrologymetrics include an angular uniformity metric, a contrast metric, anefficiency metric, a color uniformity metric, a modulation transferfunction (MTF) metric, a field of view (FOV) metric, a ghost imagemetric, an eye box metric, a display leakage metric, a see-throughdistortion metric, a see-through flare metric, a see-through ghost imagemetric, and a see-through transmittance metric. The throughput isincreased via the utilization of a feeding system coupled to each of oneor more subsystems of the optical device metrology system 200.

The optical device metrology system 200 includes a first subsystem 202,a second subsystem 204, and a third subsystem 206. Each of the firstsubsystem 202, the second subsystem 204, and the third subsystem 206include a respective body 201A-201C with a first opening 203 and asecond opening 205 to allow a stage 207 to move therethrough along astage path 211 that is parallel to and/or in the X-Y plane. The stage207 is operable to move in an X-direction, a Y-direction, and aZ-direction in the bodies 201A-201C of the first subsystem 202, thesecond subsystem 204, and the third subsystem 206. The stage 207includes a tray 209 operable to retain the optical devices 100 (as shownherein) or one or more substrates 101. The stage 207 and the tray 209may be transparent such that the metrology metrics obtained by the firstsubsystem 202, the second subsystem 204, and the third subsystem 206 arenot impacted by the translucence of the stage 207 of the tray 209. Thefirst subsystem 202, the second subsystem 204, and the third subsystem206 are in communication with a controller 208 operable to controloperation of the first subsystem 202, the second subsystem 204, and thethird subsystem 206. The controller 208 includes instructions stored ina non-transitory computer readable medium (such as a memory). Theinstructions, when executed by a processor of the controller 208, causeoperations described herein to be conducted. The instructions, whenexecuted by the processor of the controller 208, cause one or moreoperations of one or more of the methods 1000, 1100, and/or 1200 to beconducted.

The instructions of the controller 208 include a machine learningalgorithm and/or an artificial intelligence algorithm to optimizeoperations. In one embodiment, which can be combined with otherembodiments, the instructions of the controller 208 include a machinelearning (ML) model that is a regression model and averages data (suchas metrics determined herein and/or image data collected using thealignment module 494). In one example, which can be combined with otherexamples, the ML model is used to average and merge data to determineoptimized pitches and tilts for projection structures, lenses, andcameras. In one example, which can be combined with other examples, theML model is used to average and merge data to determine optimized powersto apply to light sources and laser sources to generate light beams andlaser beams.

The first subsystem 202 is operable to obtain one or more metrologymetrics including the angular uniformity metric, the contrast metric,the efficiency metric, the color uniformity metric, the MTF metric, theFOV metric, the ghost image metric, or the eye box metric. The secondsubsystem 204 is operable to obtain the display leakage metric. Thethird subsystem 206 is operable to obtain one or more see-throughmetrology metrics including the see-through distortion metric, thesee-through flare metric, the see-through ghost image metric, or thesee-through transmittance metric.

The optical device metrology system 200 is configured to determine adisplay leakage metric, one or more see-through metrics, and one or moreother metrology metrics for a plurality of optical devices (such aswaveguide combiners) on a single system using a single stage path 211.

FIG. 3A is a schematic partial cross-sectional view of the firstsubsystem 202 shown in FIG. 2, according to one implementation. Thefirst subsystem 202 may include one or more of configurations 400A,400B, 400C, 400D shown in FIGS. 4A-4D.

As shown in FIG. 3A, the first subsystem 202 includes an upper portion304 oriented toward a top side of the optical devices 100 and a lowerportion 306 oriented toward a bottom side of the optical device 100.

The first subsystem 202 includes a first body 201A having a firstopening 203 and a second opening 205 to allow the stage 207 to movethrough the first opening 203 and the second opening 205. The stage 207is configured to move the tray 209 along the stage path 211. The firstsubsystem 202 includes a first light engine 310 positioned within thefirst body 201A and mounted above the stage path 211. The first lightengine 310 is an upper light engine. The first light engine 310configured to direct first light beams toward the stage path 211. In oneembodiment, which can be combined with other embodiments, the firstlight beams are directed in a light pattern design toward the stage path211 and toward one of the optical devices 100 for determination ofmetrology metrics. The first subsystem 202 includes a first detector 312positioned within the first body 201A and mounted above the stage path211 to receive first projected light beams projected upwardly from thestage path 211. The present disclosure contemplates that projected lightcan be light that is reflected from an optical device or transmittedthrough an optical device. The first detector 312 is a reflectiondetector. The first subsystem 202 includes a second detector 316positioned within the first body 201A and mounted below the stage path211 to receive second projected light beams projected downwardly fromthe stage path 211. The second detector 316 is a transmission detector.The first projected light beams and the second projected light beams areprojected from an optical device 100. In one embodiment, which can becombined with other embodiments, the first light engine 310 isconfigured to direct the first light beams toward the input couplinggrating of an optical device 100, and the first and second detectors312, 316 are configured to receive projected light beams that projectfrom the output coupling grating of the optical device 100.

The upper portion 304 of the first subsystem 202 includes an alignmentdetector 308. The alignment detector 308 includes a camera. Thealignment detector 308 is operable to determine a position of the stage207 and the optical devices 100. The lower portion 306 of the firstsubsystem 202 includes a code reader 314 mounted below the stage path211. The code reader 314 is operable to read a code of the opticaldevices 100, such as a quick response (QR) code or barcode of an opticaldevice 100. The code read by the code reader 314 may includeinstructions for obtaining one or more metrology metrics for variousoptical devices 100.

FIG. 3B is a schematic partial cross-sectional view of the secondsubsystem 204 shown in FIG. 2, according to one implementation. Thesecond subsystem 204 may include at least one configuration 400E asshown in FIG. 4E.

As shown in FIG. 3B, the second subsystem 204 includes the upper portion304 oriented toward a top side of the optical devices 100 and a lowerportion oriented to toward a bottom side of the optical device 100.

The second subsystem 204 includes a second body 201B and a second lightengine 360 positioned within the second body 201B and mounted above thestage path 211. The second light engine 360 configured to direct secondlight beams toward the stage path 211. The upper portion 304 of thefirst subsystem 202 includes the alignment detector 308.

The second subsystem 204 includes a face illumination detector 318configured to receive third projected light beams projected upwardlyfrom the stage path 211. The third projected light beams are projectedfrom an optical device 100. The lower portion 306 of the secondsubsystem 204 includes the code reader 314.

The face illumination detector 318 is operable to capture images toobtain the display leakage metric for the optical device 100. In oneembodiment, which can be combined with other embodiments, a lightpattern design is directed from the second light engine 360 and towardthe optical device 100, and images of light outside a location of theuser's eye are obtained and processed to obtain an eye box metric.

FIG. 3C is a schematic partial cross-sectional view of the thirdsubsystem 206 shown in FIG. 2, according to one implementation. Thethird subsystem 206 may include one or more configurations 400F and/or400G as shown in FIGS. 4F and 4G.

As shown in FIG. 3C, the third subsystem 206 includes an upper portion304 oriented toward a top side of the optical devices 100 and a lowerportion 306 oriented toward a bottom side of the optical device 100. Thethird subsystem 206 includes a first light engine 370 mounted above thestage path 211 and configured to direct upper light beams toward thestage path 211, a second light engine 380 mounted below the stage path211 and configured to direct lower light beams toward the stage path211, and a detector 390 mounted above the stage path and configured toreceive projected light beams projected from the stage path 211. Theupper portion 304 of the third subsystem 206 includes the alignmentdetector 308. The detector 390 is a reflection detector. The detector390 detects projected (e.g., reflected) light beams that project (e.g.,reflect) from the output coupling grating from the top side of theoptical devices 100. The lower portion 306 of the third subsystem 206includes the code reader 314. Each of the first light engine 370, thesecond light engine 380, and the detector 390 are positioned within athird body 201C of the third subsystem 206.

FIG. 4A is a schematic view of a configuration 400A of the firstsubsystem 202 shown in FIGS. 2 and 3A, according to one implementation.The configuration 400A includes the first light engine 310, the firstdetector 312, and the second detector 316.

The first light engine 310 includes a first illuminator 401, and thefirst illuminator 401 includes a first light source 402 and a firstprojection structure 404. The first light engine 310 includes a firstlens 406 positioned between the first illuminator 401 and the stage path211. The first light engine 310 includes one or more devices 413 (one isshown in FIG. 4A) positioned between the first lens 406 and the stagepath 211. The one or more devices 413 includes one or more of a quarterwave plate or a linear polarizer. In one embodiment, which may becombined with other embodiments described herein, the first light engine310 is configured to emit (e.g., project) light beams in a red spectrum,a green spectrum, and a blue spectrum. In one example, which can becombined with other examples, the first light engine 310 is configuredto modulate or pulse light beams between the red spectrum, the greenspectrum, and the blue spectrum. In one example, which can be combinedwith other examples, the first light engine 310 includes three lightsources that are each configured to respectively emit light in the redspectrum, light in the green spectrum, and light in the blue spectrum.

The first projection structure 404 includes one or more of a displayand/or a reticle. In one embodiment, which can be combined with otherembodiments, the first projection structure 404 includes one or more ofa microdisplay, a spatial light modulator (SLM), and/or a reticle. Inone example, which can be combined with other examples, the SLM includesone or more of a digital micromirror device (DMD) and/or a liquidcrystal on silicon (LCOS) emitter.

The first detector 312 includes a first camera 412 and a second lens 410positioned between the first camera 412 and the stage path 211. Thesecond detector 316 includes a second camera 416 and a third lens 414positioned between the second camera 416 and the stage path 211. In theimplementation shown in FIG. 4A, the first projection structure 404 andthe first lens 406 are oriented parallel to the stage path 211.

The optical device 100 is positioned to align an input coupler 121 ofthe optical device 100 with the first light engine 310, and to align anoutput coupler 122 of the optical device 100 with the first detector 312and the second detector 316. First light beams B1 are directed from thefirst light engine 310 and toward the input coupler 121 of the opticaldevice 100. The first detector 312 captures a plurality of first imagesof first projected light beams BP1 that project from the output coupler122 in the red spectrum, the green spectrum, and the blue spectrum. Thesecond detector 316 captures a plurality of second images of secondprojected light beams BP2 that project from the output coupler 122 inthe red spectrum, the green spectrum, and the blue spectrum.

The first images and the second images are full-field images. One ormore of the first images and/or the second images are processed (such asby using the controller 208) to determine a plurality of first metricsof the optical device 100.

The plurality of first metrics include an angular uniformity metric. Theangular uniformity metric can represent a ratio of light intensitiesacross sections of light fields. For the angular uniformity metric, theprocessing of one or more of the plurality of first images or theplurality of second images includes comparing one or more first sectionsof a light pattern design with one or more second sections of the lightpattern design within a single image. For the angular uniformity metric,the first light beams B1 incoupled into the input coupler 121 undergoTIR until the incoupled first light beams B1 are outcoupled (e.g.,projected, such as reflected) to the first detector 312.

The plurality of first metrics include a contrast metric. The contrastmetric can represent a contrast between the brightest captured lightwithin images and the darkest captured light within images. For thecontrast metric, the processing of one or more of the plurality of firstimages or the plurality of second images includes comparing one or morebright sections of a light pattern design with one or more dark sectionsof the light pattern design within a single image. For the contrastmetric, the first light beams B1 incoupled into the input coupler 121undergo TIR until the incoupled first light beams B1 are outcoupled(e.g., projected, such as reflected) to the first detector 312.

The plurality of first metrics include a color uniformity metric. Thecolor uniformity metric can represent one or more ratios between the redlight, the green light, and the blue light in a field. One or more ofthe plurality of first images, the plurality of second images, and/orthe plurality of third images (described below in relation to FIG. 4E)capture a red spectrum, a green spectrum, and a blue spectrum. For thecolor uniformity metric, the processing of one or more of the pluralityof first images or the plurality of second images includes comparing ared spectrum image with a green spectrum image and a blue spectrum imageusing the same field area. For the color uniformity metric, the firstlight beams B1 incoupled into the input coupler 121 undergo TIR untilthe incoupled first light beams B1 are outcoupled (e.g., projected, suchas reflected) to the first detector 312.

The plurality of first metrics include an efficiency metric. For theefficiency metric, prior to the capturing of the plurality of firstimages and the capturing of the plurality of second images, the seconddetector 316 is positioned to align with the input coupler 121 of theoptical device 100 in a calibration position (shown in ghost for thesecond detector 316 in FIG. 4A). While the second detector 316 is in thecalibration position, the first light engine 310 directs calibrationlight beams toward the input coupler 121 of the optical device 100, andthe second detector 316 captures one or more calibration images ofcalibration projected light beams CP1 that project from the inputcoupler 121 of the optical device 100. The one or more calibrationimages are full-field images. The second detector 316 is then positionedto align with the output coupler 122 of the optical device 100. For theefficiency metric, the first light beams B1 incoupled into the inputcoupler 121 undergo TIR until the incoupled first light beams B1 areoutcoupled (e.g., projected, such as reflected) to the first detector312 and outcoupled (e.g., projected such as transmitted) to the seconddetector 316. The first images are reflected images and the secondimages are transmitted images.

For the efficiency metric, the processing of one or more of theplurality of first images or the plurality of second images includescomparing the one or more calibration images with the plurality of firstimages and the plurality of second images.

The one or more first metrics include a modulation transfer function(MTF) metric. For the MTF metric, prior to the capturing of theplurality of first images and the capturing of the plurality of secondimages, directing calibration light beams from the first light engine301 and toward the second detector 316. The second detector 316 capturesone or more calibration images of the calibration light beams while thesecond detector 316 is misaligned from the optical device 100. Thesecond detector 316 can be in the calibration position shown in ghost inFIG. 4A and aligned with the first light engine 310, while the opticaldevice 100 can be positioned away from the second detector 316 to be outof the fields-of-view of the second detector 316 and the first lightengine 310 (as shown in ghost for the optical device 100 in FIG. 4A).The second detector 316 can then be positioned to align with the firstdetector 312. In one embodiment, which can be combined with otherembodiments, the second images are captured prior to the capturing ofthe first images. For the MTF metric, the first light beams B1 incoupledinto the input coupler 121 undergo TIR until the incoupled first lightbeams B1 are outcoupled (e.g., projected, such as reflected ortransmitted) to the first detector 312 or the second detector 316.

For the MTF metric, the processing of one or more of the plurality offirst images or the plurality of second images includes comparing anouter edge of one or more sections of the one or more calibration imageswith the same outer edge of the same one or more sections of one or moreof the plurality of first images or the plurality of second images.

The plurality of first metrics include an eye box metric. For the eyebox metric, the first detector 312 or the second detector 316 is movedto scan across a plurality of locations along the output coupler 122 ofthe optical device 100 during the capturing of the plurality of firstimages or the capturing of the plurality of second images. Theprocessing of one or more of the plurality of first images or theplurality of second images includes comparing different images thatcorrespond to different field areas of the output coupler 122. For theeye box metric, the first light beams B1 incoupled into the inputcoupler 121 undergo TIR until the incoupled first light beams B1 areoutcoupled (e.g., projected, such as reflected or transmitted) to thefirst detector 312 or the second detector 316.

The plurality of first metrics include a ghost image metric. For theghost image metric, prior to the capturing of the plurality of firstimages and the capturing of the plurality of second images, calibrationlight beams are directed from the first light engine 310 and toward thesecond detector 316. The second detector 316 captures one or morecalibration images of the calibration light beams while the seconddetector 316 is misaligned from the optical device 100. The seconddetector 316 can be in the calibration position shown in ghost in FIG.4A and aligned with the first light engine 310, while the optical device100 can be positioned away from the second detector 316 to be out of thefields-of-view of the second detector 316 and the first light engine 310(as shown in ghost for the optical device 100 in FIG. 4A). The seconddetector 316 can then be positioned to align with the first detector312. In one embodiment, which can be combined with other embodiments,the second images are captured prior to the capturing of the firstimages.

For the ghost image metric, the processing of one or more of theplurality of first images or the plurality of second images includescomparing the one or more calibration images with one or more of theplurality of first images or the plurality of second images to determinean offset between the one or more calibration images and one or more ofthe plurality of first images or the plurality of second images. In oneembodiment, which can be combined with other embodiments, the offset isan offset between a light pattern design (such as a reticle) in the oneor more calibration images and the light pattern design (such as areticle) in the first images or the second images.

FIG. 4B is a schematic view of a configuration 400B of the firstsubsystem 202 shown in FIGS. 2 and 3A, according to one implementation.The configuration 400B includes the first light engine 310, the firstdetector 312, and the second detector 316. The first light engine 310includes the first light source 402, the first projection structure 404,and the first lens 406. The first light engine 310 in the configuration400B includes one or more two-dimensional Galvano mirrors 408 (such asan array of two-dimensional Galvano mirrors) configured to turn thefirst light beams emitted by the first projection structure 404 along a90-degree turn toward the stage path 211. In the implementation shown inFIG. 4B, the first projection structure 404 and the first lens 406 areoriented perpendicularly to the stage path 211.

The first detector 312 includes the second lens 410 and the first camera412. The second detector 316 includes the third lens 414 and the secondcamera 416. The first light engine 310, using the one or moretwo-dimensional Galvano mirrors 408, turns the first light beams B1along a 90 degree turn toward the stage path 211 and toward the inputcoupler 121 of the optical device 100.

In the implementation shown in FIG. 4B the first lens 406 is positionedbetween the first illuminator 401 and the stage path 211 along anoptical path from the first illuminator and to the stage path 211. Theone or more two-dimensional Galvano mirrors 408 are positioned betweenthe first lens 406 and the stage path 211 along the optical path. Theoptical path includes the 90 degree turn.

FIG. 4C is a schematic view of a configuration 400C of the firstsubsystem 202 shown in FIGS. 2 and 3A, according to one implementation.The configuration 400C is similar to the configuration 400A shown inFIG. 4A, and includes one or more of the aspects, features, components,and/or properties thereof.

The configuration 400C includes an alignment module 494. The alignmentmodule 494 is shown in relation to the first light engine 310 to alignthe first projection structure 404 and the first lens 406. The alignmentmodule 494 includes a laser source 495, a beam splitter 496, and analignment detector 497. The alignment module 494 includes a pinhole 498formed in a plate 499. The alignment detector 497 can include a camera.The alignment module 494 can be used in addition to the alignmentdetector 308.

The alignment module 494 is used to conduct an alignment operation. Inthe alignment operation, the first light source 402, the firstprojection structure 404 and the first lens 406 are moved out ofalignment from the input coupler 121 of the optical device 100. Thealignment module 494 directs first laser light L1 through the pinhole498 and toward the optical device 100 using the laser source 495. Alight intensity of first reflected laser light RL1 is determined usingthe alignment detector 497. The first reflected laser light RL1 is thatfirst laser light L1 that reflects off of the optical device 100. Thefirst reflected laser light RL1 is directed to the alignment detector497 using the beam splitter 496. A tilt and a pitch of the laser source495 is adjusted to increase the light intensity to an increased lightintensity. A first position of the first reflected laser light RL1received by the alignment detector 497 is determined at the increasedlight intensity. The first position is a position of the first reflectedlaser light RL1 within an image that the alignment detector 497 capturesof the first reflected laser light RL1.

In the alignment operation, the first lens 406 is moved to be alignedwith the input coupler 121 of the optical device 100 (as shown in ghostin FIG. 4C), and second laser light is directed through the pinhole 498and toward the first lens 406. A tilt and a pitch of the first lens 406is adjusted until a second position of second reflected laser lightreceived by the alignment detector matches the first position of thefirst reflected laser light RL1. The second reflected laser light is thesecond laser light that reflects off of the first lens 406 and backtoward the beam splitter 496.

In the alignment operation, the first projection structure 404 is movedto be aligned with the input coupler 121 of the optical device 100 (asshown in ghost in FIG. 4C), and third laser light is directed throughthe pinhole 498 and toward the first projection structure 404. A tiltand a pitch of the first projection structure 404 is adjusted until athird position of third reflected laser light received by the alignmentdetector matches the first position of the first reflected laser lightRL1. The third reflected laser light is the third laser light thatreflects off of the first projection structure 404 and back toward thebeam splitter 496.

The alignment module 494 can then be moved out of alignment from theinput coupler 121 of the optical device 100, and the first light source402 can be moved into alignment with the input coupler 121 of theoptical device 100. Lenses, projection structures, and cameras can bealigned using the alignment module 494 and the alignment operation tofacilitate accurate operations, such as accurate determination ofmetrics of optical devices 100. The operations described for thealignment operation can be combined with the methods 1000, 1100, 1200described below.

FIG. 4D is a schematic view of a configuration 400D of the firstsubsystem 202 shown in FIGS. 2 and 3A, according to one implementation.The configuration 400D includes the first light engine 310, the firstdetector 312, and the second detector 316. The first light engine 310includes the first light source 402, the first projection structure 404,a first lens 406 a positioned between the first illuminator 401, and alens 406 b positioned between the first lens 406 a and the stage path211. The first light engine 310 includes an adjustable aperture 407positioned between the lens 406 b and the first lens 406 a. Theadjustable aperture 407 can be formed in a plate 415. The adjustableaperture 407 can be adjusted by moving the adjustable aperture 407upward and downward (such as by moving the plate 415) and/or by openingand closing the adjustable aperture 407.

The first light engine 310 can include the one or more devices 413 shownin FIG. 4A positioned between the lens 406 b and the stage path 211. Thefirst detector 312 includes a second lens 410 and a first camera 412.The second detector 316 includes a third lens 414 and a second camera416. In one embodiment, which can be combined with other embodiments,each of the first lens 406, the first lens 406 a, the lens 406 b, thesecond lens 410 and/or the third lens 414 is formed of the same convexlens structure having the same radius of curvature. Each of the firstlens 406, the first lens 406 a, the lens 406 b, the second lens 410and/or the third lens 414 has the same lens structure. Using the samelens structure for the lenses facilitates compensating for opticaberrations, such as aberrations in reflection and/or transmission oflight.

FIG. 4E is a schematic view of a configuration 400E of the secondsubsystem 204 shown in FIGS. 2 and 3B, according to one implementation.The configuration 400E includes the second light engine 360 and the faceillumination detector 318. The second light engine 360 includes a secondilluminator 461 and a fourth lens 466 positioned between the secondilluminator 461 and the stage path 211. The second illuminator 461includes a second light source 462 and a second projection structure464. The second projection structure 464 and the fourth lens 466 areoriented parallel to the stage path 211.

The second projection structure 464 includes one or more of a displayand/or a reticle. In one embodiment, which can be combined with otherembodiments, the second projection structure 464 includes one or more ofa microdisplay, a spatial light modulator (SLM), and/or a reticle. Inone example, which can be combined with other examples, the SLM includesone or more of a digital micromirror device (DMD) and/or a liquidcrystal on silicon (LCOS) emitter.

The face illumination detector 318 includes a third camera 426, a fifthlens 424 positioned between the third camera 426 and the stage path 211,and an eye box blocker 420 positioned between the fifth lens 424 and thestage path 211. The eye box blocker 420 is adjacent a face level 422.

The optical device 100 is positioned to align the input coupler 121 withthe second light engine 360, and to align the output coupler 122 withthe face illumination detector 318. Second light beams B2 are directedfrom the second light engine 360 and toward the input coupler 121 of theoptical device 100. The face illumination detector 318 captures aplurality of third images (in addition to the first images and thesecond images described in relation to FIG. 4A) of third projected lightbeams BP3 that project from the output coupler 122 of the optical device100.

The plurality of third images include the third projected light beamsBP3 that project from the output coupler 122 of the optical device 100and past the eye box blocker 420 of the face illumination detector 318.The plurality of third images are processed (such as by using thecontroller 208) to determine one or more second metrics of the opticaldevice. The one or more second metrics include a display leakage metric.

FIG. 4F is a schematic view of a configuration 400F of the thirdsubsystem 206 shown in FIGS. 2 and 3C, according to one implementation.The third subsystem 206 includes the first light engine 310 mountedabove the stage path 211 and configured to direct upper light beamstoward the stage path 211, and a second light engine 322 mounted belowthe stage path 211 and configured to direct lower light beams toward thestage path 211.

The configuration 400F includes a detector 320 mounted above the stagepath 211 and configured to receive projected light beams projected fromthe stage path 211. The projected light beams project from the opticaldevice 100. The first light engine 310 includes the first illuminator401 and the first lens 406. The detector 320 includes the second lens410 and the first camera 412. The second light engine 322 includes adevice and a third lens.

The second light engine 322 comprises a second illuminator 471 and asecond lens 476 positioned between the second illuminator 471 and thestage path 211. The second illuminator 471 includes a second lightsource 472 and a second projection structure 474. The second projectionstructure 474 is a display or a reticle. In one embodiment, which can becombined with other embodiments, a see-through transmittance metric ofthe optical device 100 is obtained using the configuration 400F byilluminating the output coupling grating of the optical device 100 withthe lower light beams emitted by the second light engine 322.

The input coupler 121 of the optical device 100 is aligned with thefirst light engine 310 and the output coupler 122 is aligned with thesecond light engine 322, as shown in FIG. 4F. The detector 320 isaligned (e.g., vertically) with the second light engine 322 andmisaligned from the first light engine 310. The second light engine 322directs first light beams LB1 toward the output coupler 122. Upper lightbeams LB2 can be directed toward the input coupler 121 of the opticaldevice 100 from the first light engine 310. Using the detector 320, aplurality of first images are captured of the first light beams LB1 thattransmit through the output coupler 122 and project from the outputcoupler 322 as first projected light beams PB1. The optical device 100is positioned away from the second light engine 322 to misalign theoptical device 100 from the second light engine 322 (as shown in ghostin FIG. 4F for the optical device 100) and position the optical device100 out of field-of-views of the second light engine 322 and thedetector 320. Second light beams are directed from the second lightengine 322 and toward the detector 320. The detector captures aplurality of second images of the second light beams that project fromthe waveguide combiner as second projected light beams. The first imagesand the second images are full-field images. The first light beams andthe second light beams are emitted (sequentially, for example) from thelight engine in a red spectrum, a green spectrum, and a blue spectrum.The plurality of first images and the plurality of second imagesrespectively capture the first light beams and the second light beams inthe red spectrum, the green spectrum, and the blue spectrum. In oneembodiment, which can be combined with other embodiments, the secondimages are captured prior to the first images.

The second images are compared with the first images (such as by usingthe controller 208) to determine a see-through transmittance metric ofthe optical device 100. In one embodiment, which can be combined withother embodiments, the comparing includes comparing a second lightintensity of the plurality of second images with a first light intensityof the plurality of first images

FIG. 4G is a schematic view of a configuration 400G of the thirdsubsystem 206 shown in FIGS. 2 and 3C, according to one implementation.The configuration 400G includes the detector 320, and the first lightengine 310. The configuration 400G includes a patterned substrate 490positioned below the stage path 211. The patterned substrate 490includes a pattern design formed thereon. Each of the first light engine310, the patterned substrate 490, and the detector 320 are positionedwithin the third body 201C of the third subsystem 206. In oneembodiment, which can be combined with other embodiments, the patternedsubstrate 490 includes one or more of a plurality of protuberances 493and/or a plurality of recesses 489 (shown in ghost in FIG. 4G) that formthe pattern design.

In an aligned position shown in FIG. 4G, the patterned substrate 490 isaligned at least partially below the detector 320, and the patternedsubstrate 490 is misaligned at least partially from the first lightengine 310. The optical device 100 below the detector 320 to align theoptical device 100 with the detector 320, and the optical device 100 ispositioned above the patterned substrate 490 at a distance D1 from thepatterned substrate 490.

The patterned substrate 490 directs lower light beams 491 toward theoptical device 100. The lower light beams 491 are reflected off of anupper surface of the patterned substrate 490 toward the optical device100. The lower light beams 491 transmit through the optical device 100and are captured using the detector 320. In one embodiment, which can becombined with other embodiments, the patterned substrate 490 reflectsambient light as the lower light beams 491. In one embodiment, which canbe combined with other embodiments, the patterned substrate 490 reflectslight from a light engine, such as the second light engine 322. In oneembodiment, which can be combined with other embodiments, theconfiguration 400G includes the second light engine 322 configured todirect light beams toward the patterned substrate 490, and the patternedsubstrate 490 reflects the light beams from the second light engine 322as the lower light beams 491. The first light engine 310 includes thefirst light source 402, the first projection structure 404, and thefirst lens 406. The detector 320 includes the second lens 410 and thefirst camera 412.

The detector 320 captures a plurality of first images of projected lightbeams 492 that project from the output coupler 122 of the optical device100 while the patterned substrate 490 is partially aligned with thedetector 320 and partially misaligned from the detector 320 (as shown inFIG. 4G). The plurality of first images capture a red spectrum, a greenspectrum, and a blue spectrum of the projected light beams 492. Theplurality of first images are processed (such as by the controller 208)to determine one or more see-through metrics of the optical device 100.

The one or more see-through metrics include a see-through flare metric.For the see-through flare metric, the optical device 100 is positionedbelow the first light engine 310 to align the input coupler 121 of theoptical device 100 with the first light engine 310. First light beamsLB3 are directed from the first light engine 310 and toward the inputcoupler 121 of the optical device 100. In such an embodiment, theprojected light beams 492 include first light beams LB3 from the firstlight engine 310 and lower light beams 491 reflected from the patternedsubstrate 490. The first light beams LB3 are emitted from the firstlight engine 310 in a light pattern design that is different from thepattern design of the patterned substrate 490.

The one or more see-through metrics include one or more of a see-throughdistortion metric and/or a see-through transmittance metric. For thesee-through distortion metric and/or the see-through transmittancemetric, the projected light beams 492 include light beams 491 reflectedfrom the patterned substrate 490. The optical device 100 is positionedaway from the detector 320 to misalign the optical device 100 from thedetector 320 and the patterned substrate 490 (as shown in ghost for theoptical device 100 in FIG. 4G) and position the optical device 100 outof field-of-views of the patterned substrate 490 and the detector 320.The detector 320 captures a plurality of second images of reflectedlight beams that reflect from the patterned substrate 490 and toward thedetector 320. The plurality of second images capture the reflected lightbeams in the red spectrum, the green spectrum, and the blue spectrum.The processing of the plurality of first images includes comparing theplurality of second images with the plurality of first images todetermine the see-through distortion metric and/or the see-throughtransmittance metric. In one embodiment, which can be combined withother embodiments, the second images are captured prior to capturing ofthe first images.

The one or more see-through metrics include a see-through ghost imagemetric. For the see-through ghost image metric, the optical device 100is positioned away from the detector 320 to misalign the optical device100 from the detector 320 and the patterned substrate 490. The detector320 captures a plurality of second images of reflected light beams thatreflect from the patterned substrate 490 using the detector 320. Theplurality of second images capture the reflected light beams in the redspectrum, the green spectrum, and the blue spectrum. The processing ofthe plurality of first images includes determining an offset between theplurality of second images and the plurality of first images. In oneembodiment, which can be combined with other embodiments, the offset isan offset between the pattern design (such as a reticle) in the firstimages and the pattern design (such as a reticle) in the second images.

FIG. 5 is a schematic view of an image 500, according to oneimplementation. The image 500 includes a light pattern design (such as areticle) having dark sections 501 and bright sections 502. The image 500can be used to determine the contrast metric and/or the angularuniformity metric.

For the angular uniformity metric, the processing includes comparing oneor more first sections 502 a of the light pattern design with one ormore second sections 502 b, 502 c of the light pattern design within theimage 500. The first and second sections 502 a, 502 b, 502 c correspondto bright sections 502. The processing includes comparing lightintensities of the one or more first sections 502 a with lightintensities of the one or more second sections 502 b, 502 c. Thesections 502 a, 502 b, 502 c are disposed at different radii relative toa center of the image 500.

For the contrast metric, the processing includes comparing a lightintensity of one or more bright sections 502 a of the light patterndesign with a light intensity of one or more dark sections 501 a of thelight pattern design within the image 500. The bright section 502 a hasa light intensity I1 and the dark section 501 a has a light intensityI2. The contrast metric can be determined and represented by thefollowing Equation 1 as “C”:

$\begin{matrix}{C = \frac{{I\; 1} - {I\; 2}}{{I\; 1} + {I\; 2}}} & \left( {{Equation}\mspace{14mu} 1} \right)\end{matrix}$

FIGS. 6A-6C are schematic views of images 610, 620, 630, according toone implementation. FIG. 6A shows a red image 610, FIG. 6B shows a greenimage 620, and FIG. 6C shows a blue image 630. The images 610, 620, 630are used to determine the color uniformity metric. The processingincludes comparing the images 610, 620, 630 using the same field area ineach respective image 610, 620, 630. The same field area includes one ormore bright sections 602 a-602 c, 603 a-603 c at the same position ineach image 610, 620, 630. The color uniformity metric can represent aratio of light intensities of the one or more bright sections 602 a-602c, 603 a-603 c in each image 610, 620, 630.

FIGS. 7A-7C are schematic views of images 710, 720, 730, according toone implementation. FIG. 7A shows a calibration image 710, FIG. 7B showsa first image (e.g., a reflected image), and FIG. 7C shows a secondimage (e.g., a transmitted image). The images 710, 720, 730 can be usedto determine the efficiency metric.

The processing includes comparing the calibration image 710 with thefirst image 720 and the second image 730 using the same field area ineach respective image 710, 720, 730. The same field area includes one ormore bright sections 702 a-702 c at the same position in each image 710,720, 730. The processing includes comparing light intensities of the oneor more bright sections 702 a-702 c in the images 710, 720, 730. Thecalibration image 710 includes a light intensity IC1 for the brightsection 702 a, the first image 720 includes a light intensity IR1 forthe bright section 702 b, and the second image 730 includes a lightintensity IT1 for the bright section 702 c.

The efficiency metric can be determined and represented by the followingEquation 2 as “E”:

$\begin{matrix}{E = {\left( \frac{{IR}\; 1}{{IC}\; 1} \right)*\left( \frac{{IT}\; 1}{{IC}\; 1} \right)}} & \left( {{Equation}\mspace{14mu} 2} \right)\end{matrix}$

FIG. 8 is a schematic view of an image 800, according to oneimplementation. The image 800 includes a light pattern design (such as areticle) having dark sections and bright sections. The image 800 can beused to determine the MTF metric. The processing includes comparing anedge area 832 of the one or more calibration images with the same edgearea (e.g., the same position within the image) of the same one or moresections of one or more of the plurality of first images or theplurality of second images. The edge area 832 at least partiallyencompasses an outer edge 831 of one or more sections (such as a brightsection).

FIGS. 9A-9C are schematic views of images 910, 920, 930, according toone implementation. Each of the images 910, 920, 930 shows a lightpattern design that can be used for light directed by the first lightengine 310, the first light engine 370, the second light engine 360, thefirst light engine 370, the second light engine 380, the second lightengine 322, and/or the patterned substrate 490. Each of the images 910,920, 930 can be used to determine the ghost image metric and/or othermetrics (such as other first metrics). Each of the images 910, 920, 930respectively includes a plurality of dark sections 901 a-901 c and aplurality of bright sections 902 a-902 c.

FIG. 10 is a schematic block diagram view of a method 1000 of analyzingoptical devices, according to one implementation.

Operation 1002 of the method 1000 includes positioning an optical devicewithin a first subsystem to align the optical device with a firstdetector and a second detector of the first subsystem.

Operation 1004 includes directing first light beams from a first lightengine of the first subsystem and toward the optical device. In oneembodiment, which can be combined with other embodiments, the directingincludes turning the first light beams along a 90 degree turn toward thestage path.

Operation 1006 includes capturing a plurality of first images of firstprojected light beams that project from the optical device using thefirst detector of the first subsystem.

Operation 1008 includes capturing a plurality of second images of secondprojected light beams that project from the optical device using thesecond detector of the first subsystem.

Operation 1010 includes processing one or more of the plurality of firstimages or the plurality of second images to determine a plurality offirst metrics of the optical device. The first metrics include anangular uniformity metric, a contrast metric, an efficiency metric, acolor uniformity metric, a modulation transfer function (MTF) metric, afield of view (FOV) metric, a ghost image metric, and/or an eye boxmetric.

Operation 1012 includes positioning the optical device within a secondsubsystem to align the optical device with a face illumination detectorof the second subsystem.

Operation 1014 includes directing second light beams from a second lightengine of the second subsystem and toward the optical device.

Operation 1016 includes capturing a plurality of third images of thirdprojected light beams that project from the optical device using theface illumination detector of the second subsystem.

Operation 1018 includes processing the plurality of third images todetermine one or more second metrics of the optical device. The one ormore second metrics include a display leakage metric.

FIG. 11 is a schematic block diagram view of a method 1100 of analyzingoptical devices, according to one implementation.

Operation 1102 of the method 1100 includes positioning an optical deviceabove a light engine to align the optical device with the light engine.

Operation 1104 includes directing first light beams from the lightengine and toward the optical device.

Operation 1106 includes capturing a plurality of first images of thefirst light beams that project from the optical device as firstprojected light beams using a detector.

Operation 1108 includes positioning the optical device away from thelight engine to misalign the optical device from the light engine.

Operation 1110 includes directing second light beams from the lightengine and toward the detector.

Operation 1112 includes capturing a plurality of second images of thesecond light beams.

Operation 1114 includes comparing the plurality of second images withthe plurality of first images to determine a see-through transmittancemetric of the optical device.

FIG. 12 is a schematic block diagram view of a method 1200 of analyzingoptical devices, according to one implementation.

Operation 1202 of the method 1200 includes positioning an optical devicebelow a detector to align the optical device with the detector.

Operation 1204 includes positioning the optical device above a patternedsubstrate at a distance from the patterned substrate. The patternedsubstrate includes a pattern design formed thereon.

Operation 1206 includes capturing a plurality of first images ofprojected light beams that project from the optical device using adetector while the patterned substrate is at least partially alignedwith the detector.

Operation 1208 includes processing the plurality of first images todetermine one or more see-through metrics of the optical device. The oneor more see-through metrics include one or more of a see-throughtransmittance metric, a see-through distortion metric, a see-throughflare metric, and/or a see through ghost image metric.

Benefits of the present disclosure include using a single optical devicemetrology system 200 to determine multiple metrology metrics (such as adisplay leakage metric, one or more see-through metrics, and one or moreother metrology metrics) for a plurality of optical devices (such aswaveguide combiners) on a single system using a single stage path 211.In one embodiment, which can be combined with other embodiments, asingle system using a single stage path 211 can be used to determine adisplay leakage metric, an angular uniformity metric, a contrast metric,an efficiency metric, a color uniformity metric, a modulation transferfunction (MTF) metric, a field of view (FOV) metric, a ghost imagemetric, an eye box metric, a see-through distortion metric, asee-through flare metric, a see-through ghost image metric, and asee-through transmittance metric. Benefits also include increasedthroughput, reduced delays and costs, and enhanced efficiencies. Thethroughput is increased via the utilization of a feeding system coupledto each subsystem of the optical device metrology system.

It is contemplated that one or more aspects disclosed herein may becombined. As an example, one or more aspects, features, components,and/or properties of the optical device metrology system 200, the firstsubsystem 202, the second subsystem 204, the third subsystem 206, theconfiguration 400A, the configuration 400B, configuration 400C, theconfiguration 400D, the configuration 400E, the configuration 400F, theconfiguration 400G, the image 500, the images 610-630, the images710-730, the image 800, the images 910-930, the method 1000, the method1100, and/or the method 1200 may be combined. As an example, one or moreof the operations described in relation to the optical device metrologysystem 200, the subsystems 202, 204, 206, and/or the configurations400A-400G can be combined with one or more of the operations describedin relation to the method 1000, the method 1100, and/or the method 1200.Moreover, it is contemplated that one or more aspects disclosed hereinmay include some or all of the aforementioned benefits.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. An optical device metrology system, comprising: astage configured to move a tray along a stage path; a first light enginemounted above the stage path and configured to direct upper light beamstoward the stage path; a second light engine mounted below the stagepath and configured to direct lower light beams toward the stage path; adetector mounted above the stage path and configured to receiveprojected light beams projected from the stage path; and a controller incommunication with the stage, the first light engine, the second lightengine, and the detector, the controller comprising instructions that,when executed, cause: the stage to position an optical device above thesecond light engine to align the optical device with the second lightengine; the second light engine to direct first light beams from thesecond light engine and toward the optical device; the detector tocapture a plurality of first images of the first light beams thatproject from the optical device as first projected light beams; thestage to position the optical device away from the second light engineto misalign the optical device from the second light engine; the secondlight engine to direct second light beams from the second light engineand toward the detector; the detector to capture a plurality of secondimages of the second light beams; and comparing of the plurality ofsecond images with the plurality of first images to determine asee-through transmittance metric of the optical device.
 2. The opticaldevice metrology system of claim 1, wherein the upper light beams andthe lower light beams are emitted from the first light engine and thesecond light engine in a red spectrum, a green spectrum, and a bluespectrum, and the plurality of first images and the plurality of secondimages respectively capture the first light beams and the second lightbeams in the red spectrum, the green spectrum, and the blue spectrum. 3.The optical device metrology system of claim 2, wherein the second lightengine comprises an illuminator and a lens positioned between theilluminator and the stage path, the illuminator comprising a lightsource and a projection structure, the projection structure comprisingone or more of a microdisplay, a spatial light modulator (SLM), or areticle.
 4. The optical device metrology system of claim 3, wherein thedetector comprises a camera and a lens positioned between the camera andthe stage path.
 5. An optical device metrology system, comprising: astage configured to move a tray along a stage path; a first light enginemounted above the stage path and configured to direct upper light beamstoward the stage path; a second light engine mounted below the stagepath and configured to direct lower light beams toward the stage path;and a detector mounted above the stage path and configured to receiveprojected light beams projected from the stage path, the detectoraligned with the second light engine and misaligned from the first lightengine.
 6. The optical device metrology system of claim 5, furthercomprising a body having a first opening and a second opening to allowthe stage to move through the first opening and the second opening. 7.The optical device metrology system of claim 6, wherein each of thefirst light engine, the second light engine, and the detector arepositioned within the body.
 8. The optical device metrology system ofclaim 7, wherein the first light engine comprises a first illuminatorand a first lens positioned between the first illuminator and the stagepath, the first illuminator comprising a first light source and a firstprojection structure.
 9. The optical device metrology system of claim 8,wherein the first projection structure comprises one or more of amicrodisplay, a spatial light modulator (SLM), or a reticle.
 10. Theoptical device metrology system of claim 8, wherein the second lightengine comprises a second illuminator and a second lens positionedbetween the second illuminator and the stage path, the secondilluminator comprising a second light source and a second projectionstructure.
 11. The optical device metrology system of claim 10, whereinthe second projection structure comprises one or more of a microdisplay,a spatial light modulator (SLM), or a reticle.
 12. The optical devicemetrology system of claim 10, wherein the detector comprises a cameraand a third lens positioned between the camera and the stage path. 13.The optical device metrology system of claim 5, further comprising acontroller in communication with the first light engine, the secondlight engine, and the detector, the controller comprising instructionsthat, when executed, determine a see-through transmittance metric of anoptical device supported on the tray.
 14. A method of analyzing opticaldevices, comprising: positioning an optical device above a light engineto align the optical device with the light engine; directing first lightbeams from the light engine and toward the optical device; capturing aplurality of first images of the first light beams that project from theoptical device as first projected light beams using a detector;positioning the optical device away from the light engine to misalignthe optical device from the light engine; directing second light beamsfrom the light engine and toward the detector; capturing a plurality ofsecond images of the second light beams; and comparing the plurality ofsecond images with the plurality of first images to determine asee-through transmittance metric of the optical device.
 15. The methodof claim 14, wherein the first light beams and the second light beamsare emitted from the light engine in a red spectrum, a green spectrum,and a blue spectrum.
 16. The method of claim 15, wherein the pluralityof first images and the plurality of second images respectively capturethe first light beams and the second light beams in the red spectrum,the green spectrum, and the blue spectrum.
 17. The method of claim 14,wherein an output coupler of the optical device is positioned above thelight engine to align the output coupler with the light engine.
 18. Themethod of claim 17, further comprising directing upper light beams froman upper light engine and toward an input coupler of the optical device,wherein the upper light engine is positioned above the optical device.19. The method of claim 17, further comprising, prior to directing thefirst light beams, aligning the detector with the light engine.
 20. Themethod of claim 14, wherein the comparing comprises comparing a secondlight intensity of the plurality of second images with a first lightintensity of the plurality of first images.